"The car owner comes from Dagestan, he lives in the Stavropol territory, but realistically a resident of Chechnya used the car and drove it," the source said adding the man is wanted now.

The incident occurred near the Nasyr-Kortovskaya Mosque where Friday’s prayer was underway. Earlier the cause of the explosion was not named but some media assumed that a gas cylinder mounted in the car, a VAZ-2107, exploded.

A 56-year-old local resident passing inside a car by the incident site was injured. He was taken to the Ingush Republican Clinical Hospital.

The hospital told TASS that the condition of the wounded is extremely serious.

"He is in intensive care, he has a serious head injury," a spokesman said.

The car, which exploded, was nearly destroyed by the blast. A nearby house and some five other cares were damaged.

A law enforcement source told TASS that the power of the explosive device that detonated near the mosque was equivalent to at least 5 kilograms of TNT.

"There was an explosive device with the power of at least 5 kilograms [of TNT] in the car," the source said.

A crime scene investigation team is working on the site. The circumstances and causes of what happened are being clarified.

Russia’s law enforcement agencies continue fighting militants in the North Caucasus over 15 years since the battle phase of the second war against Islamist separatists in Chechnya came to an end in 2000. Attacks on security officials and civilians occur from time to time in Dagestan, Ingushetia and Kabardino-Balkaria.

On March 9, six journalists and law enforcers were hurt in an attack near Ingushetia’s administrative border with Chechnya. Four of them later sought medical assistance.

A group of journalists and human rights activists was heading for Chechnya in a Ford car. A group of 20 unidentified persons attacked them near the Ordzhonikidzovskaya settlement on the Kavkaz federal highway.

"They took away their mobile phones, set their Ford car on fire and drove away," an Ingush law enforcement source told TASS back on Wednesday.

The Presidential Council for Civil Society and Human Rights expressed its concern over the incident and demanded a quick, thorough and objective investigation into its circumstances.